STORY HIGHLIGHTS

The first bodies have been retrieved from the wreckage of the Myanmar military plane

Information indicates something went wrong soon after or just before reaching cruising altitude

Hundreds of people gathered on a beach in southern Myanmar on Thursday desperately waiting for news of their loved ones as the first bodies arrived from the wreck of a military plane that crashed with more than 120 people on board.

Navy ships and air force planes have been scouring the waves since Wednesday afternoon, when the aircraft disappeared en route from the southern city of Myeik to the commercial hub of Yangon.

By mid-afternoon the commander-in-chief's office said 29 corpses -- 20 women, one man and eight children -- had been retrieved from the sea after a navy vessel discovered wreckage from the plane off the coastline near Dawei town. Hundreds of locals, relatives and NGO workers clasping umbrellas watched as a fishing boat laden with the dead pulled up to San Hlan beach, where they were unloaded by NGO workers and uniformed soliders wearing masks and gloves.

People watching Myanmar military members carrying dead bodies at Sanhlan village (AFP)

An AFP reporter counted 29 corpses of different sizes, wrapped in black and white plastic bags, being brought onshore from the boat.

"My cousin's sister's family was in the plane crash -- her husband, her child and herself," said Kyaw Swar Myint, 44, from Dawei. "We heard news that the helicopter was now transporting about 20 dead bodies to the beach, so we are waiting here."

A military officer said strong currents has made it hard for boats to reach the shore, so many of the bodies may have to be airlifted to land. The Chinese-made Shaanxi Y8 plane was carrying a total of 122 people when it disappeared on Wednesday afternoon during a routine flight, according to the army chief.

More than half of the passengers were from military families, including 15 children, 35 soldiers and 14 crew members, the army chief's office said in a statement. Some were travelling for medical check-ups or to study in Yangon. It is monsoon season in Myanmar, but there were no major storms reported along the aircraft's flight path on Wednesday afternoon.

The office of State Counsellor Aung San Suu Kyi posted a statement expressing condolences to the victims.

India's Prime Minister Narendra Modi offered to help in recovery efforts, while the US embassy sent sympathies to the families of those lost in the 'tragedy'.

Poor safety record

The military said the plane was flying at over 18,000 feet (5,486 metres) when it lost contact with air traffic control at 1:35 pm (07:05 GMT) on Wednesday, about half an hour after takeoff. Gerry Soejatman, an independent aviation expert based in Jakarta, said the information indicated something went wrong "not long after or just before reaching cruising altitude".

The military named the captain as "seasoned" pilot Lieutenant Colonel Nyein Chan, who it said had more than 3,000 hours of flying experience. He was flying the Chinese-made, four-engine Y8 turboprop -- a medium-range transport plane based on the Soviet Antonov An-12, which has had numerous crashes over the decades.

Myanmar's former junta bought several Y8s during their 50 years of isolated rule, when they were squeezed by Western sanctions. The plane's maker, China National Aero-Technology Import & Export Corporation, in a statement pledged to assist with investigations into the crash.

The military said the plane that crashed was delivered in March 2016 and had a total of 809 flying hours.

The debris -- including two tires presumed to be from the plane were brought to shore before search efforts wrapped for the day -- was found in the Andaman Sea, north of the last known location of Malaysia Airlines flight 370. That plane went missing in March 2014 en route from Kuala Lumpur to Beijing with 239 people on board, but no wreckage has ever been found.

Myanmar's military fleet has a chequered recent history of plane crashes. A five-strong crew died when an air force plane burst into flames soon after taking off from the capital Naypyidaw in February last year. Three army officers were also killed in June when their Mi-2 helicopter crashed into a hillside and burst into flames in south-central Bago.